Health officials are concerned with an increasing number of cases in October of a polio-like disorder called acute flaccid paralysis that suddenly paralyzes a child's limbs, which flared up in an outbreak in 2015.

The National Institute of Infectious Diseases (NIID) said that a few patients across Japan typically report symptoms of paralysis each week, but the NIID received reports of nine cases from Oct. 22 to 28, following 10 the previous week.

“The number of patients, 10, for a week is too high,” said Keiko Taya, a senior researcher of the NIID’s Infectious Disease Surveillance Center.

The total number of patients reporting paralysis since May is 86. Eight cases occurred in Hyogo and Gifu prefectures. Six were in Tokyo and Aichi Prefecture, five in Fukuoka Prefecture and four in Saitama, Chiba, Kanagawa and Osaka prefectures.

Health officials advise people to make sure to wash their hands and consult with physicians as soon as symptoms appear.

Three years ago, numerous patients were infected with the enterovirus D68 (EV-D68) at the same time a number of those suffering from paralysis were reported.

The health ministry has been monitoring the situation by instructing medical institutions across Japan to report any cases since May. It is believed that EV-D68 may be the cause of the recent surge in paralysis patients.

Such patients are thought to have been infected with EV-D68, which is categorized in the group of viruses that cause polio, also called infantile paralysis, and hand, foot and mouth disease.

EV-D68 can be spread through the spray from coughs and become an epidemic from summer through autumn. Patients who contract EV-D68 will develop symptoms that are similar to that of colds including a high fever.

There is no vaccine and no effective cure, but there are stopgap treatment measures.

It takes a long time to confirm the presence of the EV-D68 agent by examining the patient's body. At this point, the virus has been detected only in part of those who are suffering from paralysis.

Since the beginning of the year, EV-D68 virus was detected in 26 patients in total including those who complained of respiratory problems, which had been reported in hospitals across Japan through Nov. 6.

The number of individuals infected with EV-D68 was six in 2017, one in 2016 and 285 in 2015.

From August to December 2015, during which cases of EV-D68 were widespread, about 60 patients suffered paralysis in their extremities and abnormalities in their medulla spinalis, even though not all were confirmed infected with EV-D68.

Of the 60 patients, four were adults and half were younger than 5. Most are still suffering paralysis.

Ryutaro Kira, who heads the department of pediatric neurology at Fukuoka Children’s Hospital and is a member of the research group of EV-D68, said, “The disease is not yet widely known. If you develop cold-like symptoms then suffer from paralysis of the limbs, I advise you to consult with a doctor. Washing the hands and gargling are essential for prevention.”